TEIID-2736: 1) Fixed the bug with nested function expressions 2) added support for boolean expressions in select clause using mongodb's  operator
Merge pull request #157 from rareddy/TEIID-2736

TEIID-2736: 1) Fixed the bug with nested function expressions 2) added s...
TEIID-2740: Adding direct query execution support for MongoDB

Conflicts:
	connectors/translator-mongodb/src/main/java/org/teiid/translator/mongodb/MongoDBExecutionFactory.java
Merge pull request #158 from rareddy/TEIID-2740

TEIID-2740: Adding direct query execution support for MongoDB